FIG. 6.

Chromosome condensation in the absence of MukEF. (A and B) Colony formation by wild-type and MukEF-deficient cells that overproduce MukB or MukBEF in minimal medium. MG1655 (A) or the ΔEF OU102 cells (B) harboring plasmid pBB10 (pB), pBB03 (pBEF), or pBAD were grown in M9 medium supplemented with 0.2% glycerol, 0.4% Casamino Acids, and 50 μg/ml ampicillin sulfate up to an OD₆₀₀ of 0.2; diluted as appropriate; and spread onto M9 plates supplemented with 0.4% Casamino Acids, 0.2% glycerol, and 50 μg/ml ampicillin sulfate with (ara) or without 0.2% arabinose. In addition, MukBEF-overproducing cells were also plated without ampicillin (−amp). The plates were incubated at either room temperature (25) or 37°C (37). The averages for at least two separate experiments are shown. Error bars indicate standard deviations. (C) Either OU102 cells harboring plasmid pBAD (ΔEF/pBAD), pBB10 (ΔEF/B), or pBB03 (ΔEF/BEF) or MG1655 cells harboring pBB10 (EF⁺/B) were grown in M9 medium supplemented with 0.4% Casamino Acids and 0.2% glycerol or in LB at room temperature. At an OD₆₀₀ of 0.2, the cells were supplemented with 0.2% arabinose, and incubation was continued for 3 hours at 37°C. The cells were then fixed and visualized by fluorescence microscopy. Arrows, anucleate cells; size bar, 5 μm.